In the recent automotive industry, according as the global interest in environment and energy is increased, there has been performed research and development in the improvement of fuel efficiency. And, in order to satisfy various users' requirements, there has been also proceeded research and development in light, small and multi-functional automobiles. In particular, in the air conditioning system for an automobile, since it is generally difficult to secure a sufficient space in an engine room, it is required that the air conditioner for an automobile has a small size and functions to effectively control temperature and air flow.
In general, the air conditioner for an automobile serves to maintain a proper temperature within the car during summer and winter seasons or removes frost and moisture generated on a window of the car during winter season and rainy day so that a driver can secure a visual field for both front and rear sides. In the air conditioner, external air is passed through an evaporator or heater core in which the cooling water is flowed, and then distributed through vents communicated with each portion in the car in a status of cool or warm air by using a ventilating part.
FIG. 1 shows a cross-sectional view of a conventional air conditioner for an automobile. The conventional air conditioner includes a case 100 having a vent 110, 120, 130 of which an opening degree is controlled by a door 110d, 120d, 130d; a ventilating part 140 which is connected with an air inlet portion of the case 100 so as to ventilate external air; an evaporator E and a heater core H provided in the case 100; and a temp door 150 for opening and closing a cool air passage P1 and a warm air passage P2 in the case 100. In the conventional air conditioner as described above, when an air cooling cycle is operated, the temp door 150 opens the coo air passage P1 and, at the same time, closes the warm air passage P2. Therefore, the air ventilated by the ventilating part 140 is heat-exchanged with the cooling water in the evaporator E, while passed through the Evaporator E, so as to be changed into the cool air. Then, the cool air is guided to the cool air passage P1 and discharged to the inside of the car through the opened vents 110, 120 and 130, thereby cooling the inside of the car.
Further, when an air heating cycle is operated, the temp door 150 closes the cool air passage P1 and, at the same time, opens the warm air passage P2. Therefore, the air ventilated by the ventilating part 140 is heat-exchanged with the cooling water in the heater core H, while passed through the Heater core H, so as to be changed into the warm air. Then, the warm air is discharged to the inside of the car through the opened vents 110, 120 and 130, thereby heating the inside of the car.
FIG. 2 is a perspective view of two kinds of conventional heater cores H, wherein FIG. 2(a) shows a U-turn type heater core and FIG. 2(b) shows a one-way type heater core. Referring to FIG. 2, the conventional heater core H includes a pair of first and second tanks 210 and 220, inlet and outlet pipes 211 and 212 which are connected to the first tank 210 or second tank 220 and through which the cooling water is introduced and discharged, a plurality of tubes 230 of which both ends are respectively fixed to the first and second tanks 210 and 220 so as to form cooling water passages, and fins 250 provided between the tubes 230.
In FIGS. 1 and 2, the same reference numerals are assigned to the same parts as those in a heater core and an air conditioner having the heater core according to the present invention.
However, in the conventional air conditioner as described above, since the evaporator and the heater core are respectively positioned at specific places, and the temp door for controlling the opening degree of each of the cool air passage and the warm air passage during the air cooling and heating cycle is provided, the space in the engine room corresponding to a radius of operation of the temp door has to be occupied, and further, since the air conditioner has a complicated structure which is an obstacle to the air flow, it is difficult to obtain the proper air flow and there is generated undesirable noise.
Furthermore, since the conventional heater core can not control an amount of cooling water introduced into the heater core, high temperature cooling water may be continuously flowed into the heater core during the air cooling cycle. Therefore, even though the warm air passage is closed by the temp door, a temperature of the external air is increased by the high temperature cooling water and thus the cooling efficiency is deteriorated.